Many wound and surgical incisions are closed using surgical sutures or some other surgical closure device. Self-retaining sutures, also known as barbed sutures, are well known and have gained attention for various medical applications. Typically, self-retaining sutures are constructed with a series of retainers (also known as “barbs” or “protrusions”, used interchangeably herein) that extend outwardly from the suture, and function to allow sutures to function without the need for knot tying.
Some sutures, including barbed sutures, have been known to include end effectors at the distal end of the suture to provide a “stop” which prevents or resists the suture from being completely pulled through tissue, while increasing the holding strength of the suture and eliminating the need to tie knots at the distal end to secure the suture. End effectors include, for example, anchors, discs, buttons, knots, tabs, loops, and the like.
Stops may be formed or modified directly from existing suture material by melting or otherwise deforming the distal end of the suture. However, thermally forming operations may undesirably alter the otherwise carefully created physical properties of the suture material immediately adjacent to the stop. For example, welding a tied knot at the end of a suture may potentially alter its crystalline structure and weaken the tensile strength adjacent to the welded structure.
Another known technique to create a stop at the end of a suture is to form the suture from a planar elongated form by removing material lateral to the central longitudinal axis to leave a core suture while leaving material lateral to the central longitudinal axis at the distal end of the suture, such as that described in U.S. Publication No. 2013/0085525. Such stops may be in the form of a tab, also known as a fixation tab. Stops formed in this manner, while eliminating the problem of altering suture properties immediately adjacent to the stop, are planar and may not present sufficient surface area parallel to tissue to adequately anchor the suture's distal end. In some instances, the sides of a stop formed in this manner may break along the length, reducing the ability to serve as an end effector.
Therefore, it would be advantageous to create a stop at the distal end of a suture without affecting the physical properties of the suture immediately adjacent to the stop. Further, there is a need for a stop with increased surface area parallel to tissue prepared in a manner that does not alter the physical properties of the suture material immediately adjacent to the stop. A composite end effector that is formed without welding or altering the molecular structure or physical properties of the suture would be useful.